RSpec 404 test respond with status 200 - ruby-on-rails

Question

I've written a test to test the 404 page
pages_controller_spec.rb
RSpec.describe PagesController, type: :controller do
before :all do
Rails.application.config.action_dispatch.show_exceptions = true
Rails.application.config.consider_all_request_local = false
end
describe "status 404" do
it "respond with 404 if page is not found" do
get :help, params: { id: "foobar" }
expect(response.status).to eq(404)
end
end
end
The pages controller is simple and functions to render the static pages "/help" and "/about"
class PagesController < ApplicationController
def help
end
def about
end
end
The error handling is set up as follows
application_controller.rb
def not_found
raise ActionController::RoutingError.new("Not Found")
rescue
render_404
end
def render_404
render file: "#{Rails.root}/public/404", status: :not_found
end
The test result is
expected: 404
got: 200
Which I do not understand since "/help/foobar" does render the 404 page when I try it myself in the browser. I guess the problem could be that my "get" action in the test is formatted wrong but I'm not sure.
EDIT
config/routes.rb as requested
get "/about", to: "pages#about"
get "/help", to: "pages#help"
EDIT 2
Updated the test with the syntax from https://relishapp.com/rspec/rspec-rails/v/3-4/docs/routing-specs/route-to-matcher
The test now looks like this
RSpec.describe PagesController, type: :controller do
before :all do
Rails.application.config.action_dispatch.show_exceptions = true
Rails.application.config.consider_all_request_local = false
end
describe "status 404" do
it "respond with 404 if page is not found" do
expect(get("/foobar")).to route_to("application#not_found")
end
end
end
Unfortuenly this raises another error
ActionController::UrlGenerationError:
No route matches {:action=>"/foobar", :controller=>"pages"}
No route is matching which is kind of the point but the "not_found" method is being used for some reason

Answer 1

Change your routes to make your call work from the browser:
get "/help/:id", to: "pages#help"
If the test returns a 200, it's because it calls directly the help method from your controller without using the config/routes.rb file.
EDIT
Here is how you test your routing: https://relishapp.com/rspec/rspec-rails/v/3-4/docs/routing-specs/route-to-matcher